Common crystal structures

Within metals, and in several other solids, a atoms are arranged within regular arrays known as crystals. A crystal structure consists of atoms arranged in a pattern which repeats periodically in a 3-dimensional geometric lattice. The forces of chemical bonding cause this repetition. It is this repeated pattern that control properties such as ductility, strength, density (defines in Module 2, Properties of Metals), conductivity (property of conducting or transmitting heat, electricity, many more.), and shape.

In common, the three most general basic crystal patterns related along with metals are as follows: (a) the body-centered cubic, (b) the face-centered cubic, and (c) the hexagonal close-packed.  Figure displays these three patterns.